/**
  ************************************* Copyright ******************************
  * FileName   : cpuusage.c
  * Version    : v1.0
  * Author     : yychao
  * Date       : 2023-02-24
  * Description:
  * Function List:
  	1. ....
  	   <version>:
  <modify staff>:
  		  <data>:
   <description>:
  	2. ...
  ******************************************************************************
 */
#include <rtthread.h>
#include <rthw.h>
#include "cpuusage.h"

#define CPU_USAGE_CALC_TICK			1000
#define CPU_USAGE_LOOP					100

static rt_uint8_t  cpu_usage_major = 0, cpu_usage_minor= 0;
static rt_uint32_t total_count = 0;

/* -------------------------------- begin  -------------------------------- */
/**
  * @Name    cpu_usage_idle_hook
  * @brief
  * @param   : [输入/出]
  * @retval
  * @author  {}
  * @Data    2023-02-24
 **/
/* -------------------------------- end -------------------------------- */

static void cpu_usage_idle_hook()
{
    rt_tick_t tick;
    rt_uint32_t count;
    volatile rt_uint32_t loop;

    if (total_count == 0) {
        /* get total count */
        rt_enter_critical();
        tick = rt_tick_get();
        /* -------------------------------- begin  -------------------------------- */
        /**
          * @Name    while
          * @brief
          * @param   : [输入/出]
          * @retval
          * @author  {}
          * @Data    2023-02-24
         **/
        /* -------------------------------- end -------------------------------- */

        while (rt_tick_get() - tick < CPU_USAGE_CALC_TICK) {
            total_count ++;
            loop = 0;
            while (loop < CPU_USAGE_LOOP) loop ++;
        }
        rt_exit_critical();
    }

    count = 0;
    /* get CPU usage */
    tick = rt_tick_get();
    while (rt_tick_get() - tick < CPU_USAGE_CALC_TICK) {
        count ++;
        loop  = 0;
        while (loop < CPU_USAGE_LOOP) loop ++;
    }

    /* calculate major and minor */
    if (count < total_count) {
        count = total_count - count;
        cpu_usage_major = (count * 100) / total_count;
        cpu_usage_minor = ((count * 100) % total_count) * 100 / total_count;
    } else {
        total_count = count;

        /* no CPU usage */
        cpu_usage_major = 0;
        cpu_usage_minor = 0;
    }
}

void cpu_usage_get(rt_uint8_t *major, rt_uint8_t *minor)
{
    RT_ASSERT(major != RT_NULL);
    RT_ASSERT(minor != RT_NULL);

    *major = cpu_usage_major;
    *minor = cpu_usage_minor;
}

void cpu_usage_init()
{
    rt_thread_idle_sethook(cpu_usage_idle_hook);
}
